In mounting the buttons that control various parameters in furnaces and similar house appliances onto the devices, there remains a gap between device body and button. This gap basically ensures that the button is rotated freely without any friction. However, this gap may also cause permeation of various liquids into the body through button gap as a result of cleaning operations on device or similar causes.
In order to overcome this shortfall, under-button gaskets were developed. The said applications were disclosed by a patent document no. EP 0 797 052. Although the applications described in the patent above basically prevent permeation of water through the said gaps, they pose a serious problem in terms of assembly and disassembly on furnace tray due to their constructions. Because they lack a part that is introduced into furnace body, or they have such parts that incorporate a section out of body, which is both short and in equal distance. During assembly of a furnace, it is quite problematic to mount such constructions to the button opening from outside of furnace tray.
However currently available sealing gaskets lose their sealing effect when they deform in time due to their flexible materials. In this case it is either impossible or quite difficult to remove and then replace them. Moreover in current applications, the gaskets limit press-rotation of buttons.
In addition to foregoing, one of the important problems is that there are no measures to prevent any foreign substances that advance toward furnace button during cleaning or in case when a meal overflows, from going through the button itself although gasket ensures a sealing with outer body.